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    <div class="refentry">
      <a id="poscil"></a>
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      <a id="Indexposcil" class="indexterm"></a>
      <div class="refnamediv">
        <h2>
          <span class="refentrytitle">poscil</span>
        </h2>
        <p>poscil — 
      High precision oscillator.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135329712"></a>
        <h2>Description</h2>
        <p>
      High precision oscillator.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135331024"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">ares <span class="command"><strong>poscil</strong></span> aamp, acps [, ifn, iphs]</pre>
        <pre class="synopsis">ares <span class="command"><strong>poscil</strong></span> aamp, kcps [, ifn, iphs]</pre>
        <pre class="synopsis">ares <span class="command"><strong>poscil</strong></span> kamp, acps [, ifn, iphs]</pre>
        <pre class="synopsis">ares <span class="command"><strong>poscil</strong></span> kamp, kcps [, ifn, iphs]</pre>
        <pre class="synopsis">ires <span class="command"><strong>poscil</strong></span> kamp, kcps [, ifn, iphs]</pre>
        <pre class="synopsis">kres <span class="command"><strong>poscil</strong></span> kamp, kcps [, ifn, iphs]</pre>
      </div>
      <div class="refsect1">
        <a id="idp135340560"></a>
        <h2>Initialization</h2>
        <p>
      <span class="emphasis"><em>ifn</em></span> -- (optional) function table number.  This
      defaults to -1 which indicates a sinewave.
    </p>
        <p>
      <span class="emphasis"><em>iphs</em></span> (optional, default=0) -- initial phase
      (normalized table index 0-1) 
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135343360"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>ares</em></span> -- output signal
    </p>
        <p>
      <span class="emphasis"><em>kamp</em></span>, <span class="emphasis"><em>aamp</em></span> -- the
      amplitude of the output signal. 
    </p>
        <p>
      <span class="emphasis"><em>kcps</em></span>, <span class="emphasis"><em>acps</em></span> -- the
      frequency of the output signal in cycles per second. 
    </p>
        <p>
      <span class="emphasis"><em>poscil</em></span> (precise oscillator) is the same as
      <a class="link" href="oscili.html" title="oscili"><em class="citetitle">oscili</em></a>, but
      allows much more precise frequency control, especially when
      using long tables and low frequency values. It uses
      floating-point table indexing, instead of integer math, like
      <span class="emphasis"><em>oscil</em></span> and <span class="emphasis"><em>oscili</em></span>.  It
      is only a bit slower than <span class="emphasis"><em>oscili</em></span>. 
    </p>
        <p>
      Since Csound 4.22, <span class="emphasis"><em>poscil</em></span> can accept also
      negative frequency values and use a-rate values both for
      amplitude and frequency. So both AM and FM are allowed using
      this opcode. 
    </p>
        <p>The opcode <a class="link" href="poscil3.html" title="poscil3"><em class="citetitle">poscil3</em></a> is the
    same as  <span class="emphasis"><em>poscil</em></span>, but uses cubic
    interpolation.</p>
        <p>Note that <span class="emphasis"><em>poscil</em></span> can use deffered
    (non-power of two) length tables.</p>
      </div>
      <div class="refsect1">
        <a id="idp135355552"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the poscil opcode. It uses the file <a class="ulink" href="examples/poscil.csd" target="_top"><em class="citetitle">poscil.csd</em></a>. 
      </p>
        <div class="example">
          <a id="idp135357328"></a>
          <p class="title">
            <strong>Example 643. Example of the poscil opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time
        Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line
        Flags</em></a> for more information on using command
        line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac     <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if RT audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o poscil.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1

<span class="ohdr">seed</span> 0
gisine <span class="ohdr">ftgen</span> 0, 0, 2^10, 10, 1

<span class="oblock">instr</span> 1

ipeak <span class="opc">random</span> 0, 1 		<span class="comment">;where is the envelope peak</span>
asig  <span class="opc">poscil</span> .8, 220, gisine
aenv  <span class="opc">transeg</span> 0, p3<span class="op">*</span>ipeak, 6, 1, p3<span class="op">-</span>p3<span class="op">*</span>ipeak, <span class="op">-</span>6, 0
aL,aR <span class="opc">pan2</span> asig<span class="op">*</span>aenv, ipeak	<span class="comment">;pan according to random value</span>
      <span class="opc">outs</span> aL, aR

<span class="oblock">endin</span>

<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">i</span>1 0 5
<span class="stamnt">i</span>1 4 5
<span class="stamnt">i</span>1 8 5
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135361792"></a>
        <h2>See Also</h2>
        <p>
      <a class="link" href="poscil3.html" title="poscil3"><em class="citetitle">poscil3</em></a>
    </p>
      </div>
      <div class="refsect1">
        <a id="idp135363936"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Gabriel Maldonado</td>
          </tr>
          <tr>
            <td>Italy</td>
          </tr>
          <tr>
            <td>1998</td>
          </tr>
        </table>
        <p>
    </p>
        <p>November 2002. Added a note about the changes to Csound
    version 4.22, thanks to Rasmus Ekman.</p>
        <p>New in Csound version 3.52</p>
        <p>Function table optional in Csound version 6.00</p>
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